Since the early development of methods of infusing liquids into patients, a problem of flow regulation has been encountered. The standard method that has been almost universally used is the elevated or hanging intravenous fluid bag or bottle. This method works fine in hospital environments where the patient is not being moved, but the same becomes very cumbersome when transport becomes necessary. This problem is even more acute in emergency situations where extra medical personnel are usually in short supply such as at accident scenes and even in ambulance and helicopter transport situations where vertical clearances may be inadequate.
To overcome the above mentioned problems, experimentation has been conducted utilizing mechanical pumps with constant tension springs to drive the same. Two of the most closely related devices of this type are shown in U.S. Pat. No. 3,670,926 to Hill and U.S. Pat. No. 3,647,117 to Hargest. In both of these patents, a variable clamp was used in an attempt to control the flow rate. Experimentation has shown, however, that in reality a fixed, repeatable, and known flow rate cannot be accomplished using devices of this type. Also, the methods of loading and unloading the infusion bag and attaching the devices in relationship to the patient were not adequate to make the same practical to use.